Casagrande, Renan, authorEdwards-Callaway, Lily, advisorHess, Tanja, advisorGrandin, Temple, committee memberWagner, John, committee memberSharp, Benjamin, committee member2021-09-062021-09-062021https://hdl.handle.net/10217/233716The objective of this study was to assess two different penetrating captive bolt gun models (Jarvis USSS-1 and USSS-21) and two stunning methods (1KNOCK and 2KNOCK, applying one and two knocks, respectively) on stunning-related variables in cattle. Heads were collected at a commercial slaughter facility and knocking efficiency, knock hole diameter, brain damage, knock hole placement and hemorrhage were assessed. Knocking efficiency was not impacted by gun model or number of knocks (P = 0.39 and 0.12, respectively). Knock number influenced knock hole diameter, brain damage and hemorrhage in the cavity (P ≤ .01). Presence of brainstem damage was greater (P < .01) when using the USSS-21 gun. Results suggested similar performance between the USSS-1 and USSS-21 gun models. Potential benefits of using the newest model could be related to damaging vital brain areas like the brainstem.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text